US8018120B2 - Surface acoustic wave device and method of fabricating the same - Google Patents

Surface acoustic wave device and method of fabricating the same Download PDF

Info

Publication number
US8018120B2
US8018120B2 US12/366,971 US36697109A US8018120B2 US 8018120 B2 US8018120 B2 US 8018120B2 US 36697109 A US36697109 A US 36697109A US 8018120 B2 US8018120 B2 US 8018120B2
Authority
US
United States
Prior art keywords
piezoelectric substrate
insulating film
electrodes
acoustic wave
saw
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related, expires
Application number
US12/366,971
Other languages
English (en)
Other versions
US20100038992A1 (en
Inventor
Akira Moriya
Osamu Kawachi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Taiyo Yuden Co Ltd
Original Assignee
Taiyo Yuden Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Taiyo Yuden Co Ltd filed Critical Taiyo Yuden Co Ltd
Assigned to FUJITSU MEDIA DEVICES LIMITED reassignment FUJITSU MEDIA DEVICES LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KAWACHI, OSAMU, MORIYA, AKIRA
Publication of US20100038992A1 publication Critical patent/US20100038992A1/en
Assigned to TAIYO YUDEN MOBILE TECHNOLOGY CO., LTD. reassignment TAIYO YUDEN MOBILE TECHNOLOGY CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FUJITSU MEDIA DEVICES LIMITED
Assigned to TAIYO YUDEN CO., LTD. reassignment TAIYO YUDEN CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TAIYO YUDEN MOBILE TECHNOLOGY CO., LTD.
Application granted granted Critical
Publication of US8018120B2 publication Critical patent/US8018120B2/en
Expired - Fee Related legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/05—Holders; Supports
    • H03H9/10—Mounting in enclosures
    • H03H9/1064—Mounting in enclosures for surface acoustic wave [SAW] devices
    • H03H9/1092—Mounting in enclosures for surface acoustic wave [SAW] devices the enclosure being defined by a cover cap mounted on an element forming part of the surface acoustic wave [SAW] device on the side of the IDT's
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/02535—Details of surface acoustic wave devices
    • H03H9/02543—Characteristics of substrate, e.g. cutting angles
    • H03H9/02574—Characteristics of substrate, e.g. cutting angles of combined substrates, multilayered substrates, piezoelectrical layers on not-piezoelectrical substrate
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/05—Holders; Supports
    • H03H9/058—Holders; Supports for surface acoustic wave devices
    • H03H9/059—Holders; Supports for surface acoustic wave devices consisting of mounting pads or bumps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/11—Manufacturing methods
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/161—Cap
    • H01L2924/162—Disposition
    • H01L2924/16235—Connecting to a semiconductor or solid-state bodies, i.e. cap-to-chip
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/42—Piezoelectric device making

Definitions

  • the present invention generally relates to surface acoustic wave devices, and more particularly, to improvements in the temperature characteristic of a surface acoustic wave device. Further, the present invention relates to a method for fabricating the above-mentioned surface acoustic wave device.
  • a surface acoustic wave device is capable of exciting an acoustic wave by applying power to comb electrodes of an interdigital transducer (IDT) formed on a piezoelectric substrate.
  • the SAW device is widely used for various circuits that process radio signals in a frequency band of, for example, 45 MHz to 2 GHz. Examples of these circuits are bandpass filters for transmission, bandpass filters for reception, local oscillation filters, antenna duplexers, intermediate frequency filters, and FM modulators.
  • the SAW device needs a cavity above a functional part (electrode fingers of IDT) of a SAW element composed of comb electrodes in order to secure the performance of the SAW element.
  • a conventional SAW device employs a ceramic package having a recess in which the SAW element is mounted. A metal lid covers the recess, so that a cavity can be defined above the functional part of the SAW element. Wire bonding is used to make electrical connections between the SAW element and interconnections provided on the ceramic package.
  • wire bonding uses wires, which prevents downsizing of the SAW device.
  • flip-chip bonding is developed. Flip-chip bonding realizes downsizing because of wireless mounting.
  • Japanese Patent Application Publication No. 2000-261284 describes a SAW element provided on a surface of a piezoelectric substrate. A cover is provided on the surface of the piezoelectric substrate in order to define a cavity above the functional part of the SAW element. The cover is used as a package. This type of packaging is called wafer level package (WLP). This realizes further miniaturization.
  • WLP wafer level package
  • the SAW device using the piezoelectric substrate has a problem such that the frequency characteristic is affected due to expansion and contraction of the piezoelectric substrate.
  • the frequency characteristic of the SAW device is more greatly affected as the piezoelectric substrate has a greater amount of expansion and contraction.
  • the piezoelectric substrate expands and contracts with the amount of expansion and contraction that depends on the linear expansion coefficient due to temperature change.
  • the piezoelectric substrate may be typically made of lithium tantalate (LiTaO 3 ) or lithium niobate (LiNbO 3 ), which has a great electro-mechanical coupling coefficient. However, these substrates have great linear expansion coefficients, and greatly expand and contract due to temperature change.
  • a surface acoustic wave device including: a piezoelectric substrate; comb electrodes provided on a first surface of the piezoelectric substrate; and an insulating film provided on at least one of the first surface of the piezoelectric substrate and a second surface thereof opposite to the first surface, the insulating film having a thickness greater than that of the piezoelectric substrate and having a linear expansion coefficient smaller than that of the piezoelectric substrate in a direction of propagation of a surface acoustic wave.
  • a method of fabricating a surface acoustic wave device including: forming comb electrodes on a first surface of a piezoelectric substrate; thinning the piezoelectric substrate after the comb electrodes are formed; and forming an insulating film on at least one of the first surface of the piezoelectric substrate and a second surface thereof opposite to the first surface, the insulating film having a thickness greater than that of the piezoelectric substrate and having a linear expansion coefficient smaller than that of the piezoelectric substrate in a direction of propagation of a surface acoustic wave.
  • FIG. 1 is a cross-sectional view of a SAW device in accordance with a first embodiment of the present invention
  • FIGS. 2A through 2D are cross-sectional views that illustrate a first part of a method of fabricating the SAW device in accordance with the first embodiment
  • FIGS. 3A through 3C are cross-sectional views that illustrate a second part of the method following the first part
  • FIG. 4 is a graph that describes a temperature dependence of frequency of the SAW device in accordance with the first embodiment
  • FIG. 5 is a cross-sectional view of a SAW device in accordance with a second embodiment of the present invention.
  • FIGS. 6A through 6C are cross-sectional views that illustrate a first part of a method of fabricating the SAW device in accordance with the second embodiment
  • FIGS. 7A through 7C are cross-sectional views that illustrate a second part of the method following the first part
  • FIG. 8 is a cross-sectional view of a SAW device in accordance with a third embodiment.
  • FIG. 9 is a cross-sectional view of a SAW device in accordance with a fourth embodiment.
  • FIG. 1 is a cross-sectional view of a SAW device in accordance with a first embodiment of the present invention taken along a line so that cross sections of comb electrodes and column electrodes appear.
  • a SAW device 10 has a piezoelectric substrate 12 having a main surface on which comb electrodes 14 and reflection electrodes (not shown for the sake of simplicity) are provided.
  • the piezoelectric substrate 12 may be made of lithium tantalate (LiTaO 3 ) or lithium niobate (LiNbO 3 ).
  • the comb electrodes 14 and the reflection electrodes may be aluminum (Al) or an Al alloy with copper (Cu) being added.
  • Interconnection electrodes 16 are provided on the main surface of the piezoelectric substrate 12 and are electrically connected to the comb electrodes 14 .
  • the interconnection electrodes 16 may be made of Al or an Al alloy with copper being added.
  • a resin portion 20 is provided on the main surface of the piezoelectric substrate 12 so as to define cavities 18 provided above the comb electrodes 14 .
  • the resin portion 20 may be made of epoxy resin.
  • Column electrodes 22 are provided on the interconnection electrodes 16 and pass through the resin portion 20 .
  • the column electrodes 22 may be made of copper, nickel (Ni) or gold (Au).
  • Solder bumps 24 are provided on the column electrodes 22 .
  • the combinations of the column electrodes 22 and the solder bumps 24 function as terminals for making electrical connections with external parts in flip-chip mounting of the SAW device.
  • An insulating film 26 is provided on the back surface of the piezoelectric substrate 12 .
  • the thickness of the insulating film 26 is greater than that of the piezoelectric substrate 12 .
  • the insulating film 26 is made of a substance having a thermal expansion coefficient smaller than that of the piezoelectric substrate 12 in the direction of SAW propagation.
  • the insulating film 26 may be made of alumina (Al 2 O 3 ).
  • the piezoelectric substrate 12 is in the form of a wafer on which there are regions from which multiple SAW devices 10 are derived. For the sake of simplicity, only one of the multiple SAW devices 10 is illustrated in FIGS. 2A through 3C .
  • the wafer is divided into parts along dicing regions so that the SAW devices on the wafer can be separated from each other.
  • the comb electrodes 14 , the reflection electrodes (not depicted) and the interconnection electrodes 16 are formed on the main surface of the piezoelectric substrate 12 .
  • the comb electrodes 14 , the reflection electrodes and the interconnection electrodes 16 may be made of Al or an Al alloy with Cu being added, and may, for example, be 0.1-0.5 ⁇ m thick.
  • a grinding or sand blast process is carried out from the back surface of the piezoelectric substrate 12 in order to thin the piezoelectric substrate 12 .
  • the piezoelectric substrate may, for example, be 30 ⁇ m-40 ⁇ m thick after the thinning process.
  • the insulating film 26 is formed on the back surface of the piezoelectric substrate 12 while the main surface of the piezoelectric substrate 12 is protected in order to prevent the comb electrodes 14 , the reflection electrodes and the interconnection electrodes 16 from being functionally damaged.
  • the insulating film 26 may be made of ceramics such as alumina (Al 2 O 3 ), and may, for example, be 200-350 ⁇ m thick.
  • the insulating film 26 may be formed by plasma spraying or aerosol deposition.
  • nega-type photosensitive epoxy resin 20 a is applied to the main surface of the piezoelectric substrate 12 and is baked.
  • the epoxy resin 20 a may be applied by spin coating.
  • Ultraviolet ray is applied to the epoxy resin 20 a with a mask. In this application, the UV ray is not applied to regions in which the cavities 18 above the comb electrodes 14 should be formed and regions in which the column electrodes 22 should be formed above the interconnection electrodes 16 .
  • the epoxy resin 20 a is developed to remove the epoxy resin 20 a in the regions to which the UV ray is not applied. This results in openings 28 in the regions in which the cavities 18 should be formed and the regions in which the column electrodes 22 should be formed.
  • the epoxy resin 20 a is annealed at 200° C. for one hour in a nitrogen atmosphere and is thus cured.
  • nega-type photosensitive epoxy resin 20 b is formed on the epoxy resin 20 a so as to cover the openings 28 .
  • the epoxy resin 20 b may be formed by, for example, pressure rolling such as a laminator.
  • the UV ray is applied to the epoxy resin 20 b with a mask. In this application, the UV ray is not applied to the regions in which the column electrodes 22 above the interconnection electrodes 16 should be formed.
  • the epoxy resin 20 b is developed to remove the epoxy resin 20 b in the regions on which the UV ray is not applied.
  • the epoxy resin 20 b is annealed at 200° C. for one hour in a nitrogen atmosphere and is thus cured. This results in the resin portion 20 that is formed by the epoxy resin 20 a and the epoxy resin 20 b and is equipped with the cavities 18 above the comb electrodes 14 and openings above the interconnection electrodes 16 .
  • the openings 30 are filled with a metal of, for example, Cu, Ni or Au to form the column electrodes 22 .
  • This process may use electrolytic plating or electroless plating. Squeegee printing on the resin portion 20 may be employed to form the column electrodes 22 in the openings 30 .
  • the solder bumps 24 are formed on the column electrodes 22 .
  • the solder bumps 24 may be SnAg solder balls. Then, the wafer is cut into pieces by dicing in the dicing regions so that the individual SAW devices 10 of the WLP structure can be obtained.
  • FIG. 4 is a graph of a temperature dependence of frequency of a filter using the SAW devices configured by the first embodiment.
  • FIG. 4 further depicts a comparative example of the temperature dependence of frequency of a filter using the conventional SAW devices.
  • Table 1 describes the particulars of the SAW devices of the first embodiment and those of the conventional SAW devices used in measurement.
  • the SAW devices of the first embodiment use the piezoelectric substrate 12 that is 40 ⁇ m thick and is made of LiTaO 3 and the insulating film 26 that is 310 ⁇ m thick and is made of alumina (Al 2 O 3 ).
  • the insulating film 26 of alumina is formed by plasma spraying.
  • the other specifications are the same as those that have been described with reference to FIG. 1 .
  • the SAW devices of the comparative example uses the piezoelectric substrate 12 that is 180 ⁇ m thick and is made of LiTaO 3 , but does not have the insulating film 26 .
  • the other specifications are similar to those of the first embodiment used in measurement.
  • the horizontal axis of the graph of FIG. 4 denotes the temperature (° C.), and the vertical axis denotes frequency variation (ppm).
  • a solid line in FIG. 4 is the measurement result for the SAW devices of the first embodiment, and a broken line is the measurement result for the conventional SAW devices.
  • the measurement is carried out at the center frequency of the pass band (approximately equal to 1 GHz) of the filters. It can be seen from FIG. 4 that the filter using the SAW devices of the first embodiment has a smaller frequency variation than that of the filter using the conventional SAW devices due to temperature change.
  • the comb electrodes 14 are formed on the main surface of the piezoelectric substrate 12 , and the insulating film 26 that is thicker than the piezoelectric substrate 12 is provided on the back surface of the piezoelectric substrate 12 .
  • the insulating film 26 is made of a substance having a thermal expansion coefficient smaller than that of the piezoelectric substrate 12 in the direction of SAW propagation.
  • the thermal expansion coefficient of LiTaO 3 for the piezoelectric substrate 12 is approximately 16 ppm/° C.
  • alumina for the insulating film 26 is approximately 7 ppm/° C.
  • the piezoelectric substrate 12 When the piezoelectric substrate 12 is used alone, it has an amount of expansion and contraction that depends on the thermal expansion coefficient of the piezoelectric substrate 12 . In contrast, the piezoelectric substrate 12 with the insulating film 26 being added to the backside thereof has restrained expansion and contraction due to the presence of the insulating film 26 . It is thus possible to reduce frequency variation due to temperature change, as illustrated in FIG. 4 , and to produce the SAW devices having improved temperature characteristics.
  • the comb electrodes 14 are formed on the main surface of the piezoelectric substrate 12 , as illustrated in FIG. 2A . Thereafter, the piezoelectric substrate 12 is thinned, as illustrated in FIG. 2B . Then, the insulating film 26 is formed on the back surface of the piezoelectric substrate 12 by spraying or aerosol deposition, as illustrated in FIG. 2C . For example, in a case where the insulating film 26 is formed on the back surface of the piezoelectric substrate 12 by bonding, the comb electrodes 14 are formed on the main surface of the piezoelectric substrate 12 after bonding.
  • the presence of the insulating film 26 on the piezoelectric substrate 12 may increase warpage of the piezoelectric substrate 12 .
  • the comb electrodes 14 are formed on the main surface of the piezoelectric substrate 12 before the insulating film 26 is formed. It is thus possible to easily perform patterning of the comb electrodes 14 on the piezoelectric substrate 12 that is not yet warped greatly. Spraying or aerosol deposition is capable of reliably forming the insulating film 26 on the back surface of the piezoelectric substrate 12 without affecting the comb electrodes 14 on the surface of the piezoelectric substrate 12 that has been thinned. Further, thinning of the piezoelectric substrate 12 causes it to be increasingly influenced by the insulating film 26 and more greatly restrains expansion and contraction due to temperature change.
  • the cavities 18 provided above the comb electrodes 14 are defined by the resin portion 20 made of photosensitive epoxy resin. It is thus possible to form the cavities 18 easily.
  • a second embodiment has an exemplary structure in which the insulating film 26 is formed on the main surface of the piezoelectric substrate 12 .
  • FIG. 5 is a cross-sectional view of a SAW device in accordance with the second embodiment taken along a line so that cross sections of the comb electrodes 14 and the column electrodes appear.
  • the SAW device 10 has the piezoelectric substrate 12 having the main surface on which the comb electrodes 14 , the reflection electrodes (not illustrated) and the interconnection electrodes 16 are formed.
  • the comb electrodes 14 and the interconnection electrodes 16 are electrically connected.
  • the resin portion 20 is provided on the surface of the piezoelectric substrate 12 so that the cavities 18 can be defined above the comb electrodes 14 .
  • the insulating film 26 is thicker than the piezoelectric substrate 12 , and has a linear expansion coefficient greater than that of the piezoelectric substrate 12 in the direction of SAW propagation.
  • the column electrodes 22 are provided on the interconnection electrodes 16 so as to pass through the insulating film 26 .
  • the solder bumps 24 are provided on the column electrodes 22 .
  • the piezoelectric substrate 12 is in the form of a wafer on which there are regions from which multiple SAW devices 10 are derived. For the sake of simplicity, only one of the multiple SAW devices 10 is illustrated in FIGS. 6A through 7C .
  • the wafer is divided into parts along dicing regions so that the SAW devices on the wafer can be separated from each other.
  • the fabrication steps of FIGS. 2A and 2B related to the first embodiment are carried out.
  • the resin portion 20 is formed on the main surface of the piezoelectric substrate 12 so as to define the cavities 18 above the comb electrodes 14 .
  • the resin portion 20 may be formed by the method that has been described with reference to FIGS. 2D and 3A .
  • photoresist 36 is applied to the surface of the piezoelectric substrate 12 and is then baked. Then, exposure, development and baking are carried out to define openings 38 in regions in which the column electrodes 22 should be formed above the interconnection electrodes 16 .
  • the column electrodes 22 are formed so as to be buried in the openings 38 .
  • the photoresist 36 is removed and the insulating film 26 is formed on the main surface of the piezoelectric substrate 12 so as to cover the resin portion 20 and the column electrodes 22 .
  • the insulating film 26 may be formed by plasma spraying or aerosol deposition.
  • the insulating film 26 is thinned by grinding or sand blast until the surfaces of the column electrodes 22 appear.
  • the solder bumps 24 are formed on the column electrodes 22 .
  • the piezoelectric substrate 12 in the form of wafer is divided in pieces by dicing, so that the SAW devices 10 of the WLP structure in accordance with the second embodiment can be completed.
  • the SAW device 10 has the insulating film 26 provided on the piezoelectric substrate 12 in which the insulating film 26 has a thickness greater than that of the piezoelectric substrate 12 and a thermal expansion coefficient smaller than that of the piezoelectric substrate 12 in the direction of SAW propagation. It is thus possible to restrain expansion and contraction of the piezoelectric substrate 12 due to temperature change and improve the temperature characteristics.
  • the insulating film 26 is formed so as to cover the resin portion 20 on the surface of the piezoelectric substrate 12 .
  • the cavities 18 above the comb electrodes 14 are defined by the resin portion 20 . If the insulating film 26 is formed so as not to cover the resin portion 20 , the resin portion 20 may be dented due to external pressure and the cavities 18 may be crashed.
  • the second embodiment employs the insulating film 26 so as to cover the resin portion 20 , so that the resin portion 20 can be reinforced to prevent the cavities 18 from being crashed.
  • a third embodiment has an exemplary structure in which the insulating films 26 are provided on both the front and back surfaces of the piezoelectric substrate 12 .
  • FIG. 8 is a cross-sectional view of a SAW device in accordance with the third embodiment taken along a line so that the cross sections of the comb electrodes 14 and the column electrodes 22 appear.
  • the SAW device 10 has the piezoelectric substrate 12 on which the comb electrodes 14 , the reflection electrodes (not illustrated) and the interconnection electrodes 16 are formed.
  • the comb electrodes 14 and the interconnection electrodes 16 are electrically connected.
  • the resin portion 20 is formed on the main surface of the piezoelectric substrate 12 so that the cavities 18 can be defined above the comb electrodes 14 .
  • the insulating film 26 is formed on the main surface of the piezoelectric substrate 12 so as to cover the resin portion 20 .
  • the column electrodes 22 are formed on the interconnection electrodes 16 so as to pass through the insulating film 26 on the main surface of the piezoelectric substrate 12 .
  • the solder bumps 24 are formed on the column electrodes 22 .
  • the insulating film 26 is provided on the back surface of the piezoelectric substrate 12 .
  • the insulating films 26 provided on both the front and back surfaces of the piezoelectric substrate 12 have a thickness greater than that of the piezoelectric substrate 12 and have a smaller linear expansion coefficient than that of the piezoelectric substrate 12 in the direction of SAW propagation.
  • FIGS. 2A through 2C described in connection with the first embodiment are carried out.
  • FIGS. 6A through 7C described in connection with the second embodiment are carried out.
  • the SAW device 10 of the WLP structure is completed.
  • the insulating films 26 are formed on both the front and back surfaces of the piezoelectric substrate 12 . It is thus possible to greatly suppress expansion and contraction of the piezoelectric substrate 12 due to temperature change, as compared to the first and second embodiments and to obtain the SAW device having further improved temperature characteristics.
  • the insulating film 26 formed on the main surface of the piezoelectric substrate 12 covers the entire resin portion 20 , as illustrated in FIG. 8 . It is thus possible to reinforce the resin portion 20 and prevent the cavities 18 from being crashed.
  • the insulating films 26 formed on both the front and back surfaces of the piezoelectric substrate 12 may be made of an identical material or different materials.
  • a fourth embodiment has an exemplary structure in which an insulating film 26 a made of ceramics containing glass is formed on the back surface of the piezoelectric substrate 12 .
  • FIG. 9 is a cross-sectional view of a SAW device in accordance with the fourth embodiment.
  • the piezoelectric substrate 12 is in the form of a wafer on which there are regions from which multiple SAW devices 10 are derived. For the sake of simplicity, only one of the multiple SAW devices 10 is illustrated in FIG. 9 .
  • the fabrication steps of FIGS. 2A through 2C are carried out.
  • the insulating film 26 a made of ceramics containing glass is formed on the back surface of the piezoelectric substrate 12 .
  • Glass may be contained in ceramics by spin coating in which ceramics is coated with silanol compound liquid solution and is then baked. The silanol compound liquid solution sinks in ceramics so that the insulating film 26 a made of ceramics containing glass can be obtained.
  • the fabrication steps illustrated in FIGS. 2D through 3C are carried out, so that the SAW device 10 of the WLP structure can be completed in accordance with the fourth embodiment.
  • the insulating film 26 a made of ceramics containing glass is formed on the back surface of the piezoelectric substrate 12 .
  • the insulating film 26 a has a greater Young's module than that of an insulating film that does not contain glass. As the Young's module increases, the insulating film is harder and is more indeformable. It is thus possible to further restrain expansion and contraction of the piezoelectric substrate 12 due to temperature change by employing the insulating film 26 a having a great Young's module on the back surface of the piezoelectric substrate 12 and to realize the SAW device having further improved temperature characteristics.
  • the insulating film 26 a of ceramics containing glass is not formed on the back surface of the piezoelectric substrate 12 but on the main surface thereof. It is also possible to form the insulating films 26 a on both the front and back surfaces of the piezoelectric substrate 12 . These variations are capable of further suppressing expansion and contraction of the piezoelectric substrate 12 due to temperature change and providing the SAW device having further improved temperature characteristics.
  • At least one of the front and back surfaces of the thinned piezoelectric substrate 12 is provided with the insulating film 26 .
  • the piezoelectric substrate 12 may not be thinned. Even when the piezoelectric substrate 12 that is not thinned is used, it is possible to restrain expansion and contraction of the piezoelectric substrate 12 and to realize the SAW device having improved temperature characteristics.

Landscapes

  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
US12/366,971 2008-02-08 2009-02-06 Surface acoustic wave device and method of fabricating the same Expired - Fee Related US8018120B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008-028269 2008-02-08
JP2008028269A JP4460612B2 (ja) 2008-02-08 2008-02-08 弾性表面波デバイス及びその製造方法

Publications (2)

Publication Number Publication Date
US20100038992A1 US20100038992A1 (en) 2010-02-18
US8018120B2 true US8018120B2 (en) 2011-09-13

Family

ID=40977259

Family Applications (1)

Application Number Title Priority Date Filing Date
US12/366,971 Expired - Fee Related US8018120B2 (en) 2008-02-08 2009-02-06 Surface acoustic wave device and method of fabricating the same

Country Status (3)

Country Link
US (1) US8018120B2 (ja)
JP (1) JP4460612B2 (ja)
CN (1) CN101505143B (ja)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100052473A1 (en) * 2008-08-26 2010-03-04 Fujitsu Media Devices Limited Acoustic wave device and method for manufacturing the same
US20140015373A1 (en) * 2011-03-22 2014-01-16 Murata Manufacturing Co., Ltd. Method for manufacturing electronic component module and electronic component module
US20140339956A1 (en) * 2012-08-01 2014-11-20 Murata Manufacturing Co., Ltd. Electronic component and electronic component module

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009078137A1 (ja) * 2007-12-14 2009-06-25 Murata Manufacturing Co., Ltd. 表面波装置及びその製造方法
JP2012160979A (ja) * 2011-02-01 2012-08-23 Taiyo Yuden Co Ltd 弾性波デバイス及びその製造方法
WO2012120968A1 (ja) 2011-03-09 2012-09-13 株式会社村田製作所 電子部品
US9293684B2 (en) * 2011-07-29 2016-03-22 Kyocera Corporation Electronic part comprising acoustic wave device
DE102012101889A1 (de) * 2012-03-06 2013-09-12 Osram Opto Semiconductors Gmbh Verfahren zur Herstellung eines optoelektronischen Halbleiterchips und optoelektronischer Halbleiterchip
JP6103906B2 (ja) 2012-12-06 2017-03-29 スカイワークスフィルターソリューションズジャパン株式会社 弾性波装置と封止体
JP6242597B2 (ja) 2013-06-03 2017-12-06 太陽誘電株式会社 弾性波デバイス及びその製造方法
JP2015046870A (ja) * 2013-07-31 2015-03-12 株式会社村田製作所 弾性波装置の製造方法
CN105474539B (zh) * 2013-08-20 2017-12-01 株式会社村田制作所 声表面波设备及其制造方法
JP2014033467A (ja) * 2013-10-31 2014-02-20 Murata Mfg Co Ltd 弾性表面波素子
DE112014006080B4 (de) 2013-12-27 2022-05-12 Murata Manufacturing Co., Ltd. Vorrichtung für elastische Wellen
WO2015098679A1 (ja) 2013-12-27 2015-07-02 株式会社村田製作所 弾性波装置及びその製造方法
JP6516005B2 (ja) * 2015-06-25 2019-05-22 株式会社村田製作所 弾性波装置
FR3045933B1 (fr) * 2015-12-22 2018-02-09 Soitec Substrat pour un dispositif a ondes acoustiques de surface ou a ondes acoustiques de volume compense en temperature
WO2017110993A1 (ja) * 2015-12-25 2017-06-29 株式会社村田製作所 高周波モジュール
JP7397611B2 (ja) * 2019-09-26 2023-12-13 太陽誘電株式会社 電子デバイス
CN111934649B (zh) * 2020-09-16 2021-02-23 苏州日月新半导体有限公司 集成电路装置及其制造方法
CN117713741B (zh) * 2024-02-04 2024-06-25 深圳新声半导体有限公司 薄膜表面声波滤波器及其制作方法

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3916348A (en) * 1975-01-31 1975-10-28 Rca Corp Temperature-compensated surface-propagated wave energy device
US3965444A (en) * 1975-01-03 1976-06-22 Raytheon Company Temperature compensated surface acoustic wave devices
US4699682A (en) * 1985-10-23 1987-10-13 Clarion Co., Ltd. Surface acoustic wave device sealing method
US5059848A (en) * 1990-08-20 1991-10-22 The United States Of America As Represented By The Secretary Of The Army Low-cost saw packaging technique
JP2000261284A (ja) 1999-03-05 2000-09-22 Kyocera Corp 弾性表面波装置及びその製造方法
WO2007059733A1 (de) 2005-11-23 2007-05-31 Epcos Ag Elektroakustisches bauelement
US20070120623A1 (en) 2005-11-30 2007-05-31 Kazuyuki Sakiyama Surface acoustic wave device and communication terminal using the same
US7408286B1 (en) * 2007-01-17 2008-08-05 Rf Micro Devices, Inc. Piezoelectric substrate for a saw device
JP2009021701A (ja) 2007-07-10 2009-01-29 Koike Co Ltd 圧電基板の製造方法
US7564174B2 (en) * 2006-09-11 2009-07-21 Fujitsu Media Devices Limited Acoustic wave device and filter
US7772742B2 (en) * 2006-05-30 2010-08-10 Murata Manufacturing Co., Ltd. Boundary acoustic wave device

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001111378A (ja) * 1999-10-13 2001-04-20 Toyo Commun Equip Co Ltd 弾性表面波素子及び弾性表面波デバイス
JP2002261582A (ja) * 2000-10-04 2002-09-13 Matsushita Electric Ind Co Ltd 弾性表面波デバイスおよびその製造方法ならびにそれを用いた回路モジュール
JP4496652B2 (ja) * 2001-02-06 2010-07-07 パナソニック株式会社 弾性表面波装置とその製造方法
CN101361267B (zh) * 2006-01-18 2011-09-14 株式会社村田制作所 弹性表面波装置和弹性边界波装置

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3965444A (en) * 1975-01-03 1976-06-22 Raytheon Company Temperature compensated surface acoustic wave devices
US3916348A (en) * 1975-01-31 1975-10-28 Rca Corp Temperature-compensated surface-propagated wave energy device
US4699682A (en) * 1985-10-23 1987-10-13 Clarion Co., Ltd. Surface acoustic wave device sealing method
US5059848A (en) * 1990-08-20 1991-10-22 The United States Of America As Represented By The Secretary Of The Army Low-cost saw packaging technique
JP2000261284A (ja) 1999-03-05 2000-09-22 Kyocera Corp 弾性表面波装置及びその製造方法
US20080292127A1 (en) 2005-11-23 2008-11-27 Werner Ruile Electroacoustic Component
WO2007059733A1 (de) 2005-11-23 2007-05-31 Epcos Ag Elektroakustisches bauelement
US20070120623A1 (en) 2005-11-30 2007-05-31 Kazuyuki Sakiyama Surface acoustic wave device and communication terminal using the same
CN1976223A (zh) 2005-11-30 2007-06-06 日立视听媒介电子股份有限公司 弹性表面波装置和搭载其的通信终端
US7675387B2 (en) * 2005-11-30 2010-03-09 Hitachi Media Electronics Co., Ltd. Surface acoustic wave device and communication terminal using the same
US7772742B2 (en) * 2006-05-30 2010-08-10 Murata Manufacturing Co., Ltd. Boundary acoustic wave device
US7564174B2 (en) * 2006-09-11 2009-07-21 Fujitsu Media Devices Limited Acoustic wave device and filter
US7408286B1 (en) * 2007-01-17 2008-08-05 Rf Micro Devices, Inc. Piezoelectric substrate for a saw device
JP2009021701A (ja) 2007-07-10 2009-01-29 Koike Co Ltd 圧電基板の製造方法

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100052473A1 (en) * 2008-08-26 2010-03-04 Fujitsu Media Devices Limited Acoustic wave device and method for manufacturing the same
US8154170B2 (en) * 2008-08-26 2012-04-10 Taiyo Yuden Co., Ltd. Acoustic wave device and method for manufacturing the same
US20140015373A1 (en) * 2011-03-22 2014-01-16 Murata Manufacturing Co., Ltd. Method for manufacturing electronic component module and electronic component module
US9590586B2 (en) * 2011-03-22 2017-03-07 Murata Manufacturing Co., Ltd. Electronic component module
US20140339956A1 (en) * 2012-08-01 2014-11-20 Murata Manufacturing Co., Ltd. Electronic component and electronic component module
US9711708B2 (en) * 2012-08-01 2017-07-18 Murata Manufacturing Co., Ltd Electronic component having a reinforced hollowed structure
US10593861B2 (en) 2012-08-01 2020-03-17 Murata Manufacturing Co., Ltd. Electronic component having a reinforced hollowed structure

Also Published As

Publication number Publication date
JP2009188844A (ja) 2009-08-20
CN101505143B (zh) 2012-04-18
CN101505143A (zh) 2009-08-12
JP4460612B2 (ja) 2010-05-12
US20100038992A1 (en) 2010-02-18

Similar Documents

Publication Publication Date Title
US8018120B2 (en) Surface acoustic wave device and method of fabricating the same
US9882540B2 (en) Method for manufacturing surface acoustic wave apparatus
JP6290850B2 (ja) 弾性波装置および弾性波モジュール
US7586240B2 (en) Acoustic wave device
US20100045145A1 (en) Piezoelectric component and manufacturing method thereof
EP2267895B1 (en) Electronic component, circuit board, electronic apparatus, and method for manufacturing the electronic component
US20110115339A1 (en) Acoustic Wave Device
US8004160B2 (en) Acoustic wave device with adhesive layer and method of manufacturing the same
JP2012182604A (ja) 弾性波フィルタ部品
US20080122314A1 (en) Acoustic wave device
KR100891418B1 (ko) 탄성파 디바이스 및 그 제조 방법
JP2000312127A (ja) 弾性表面波装置
US20090175470A1 (en) Acoustic wave device and method of manufacturing the same
JP2010034782A (ja) 弾性境界波デバイスおよびその製造方法、デュープレクサの製造方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: FUJITSU MEDIA DEVICES LIMITED,JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MORIYA, AKIRA;KAWACHI, OSAMU;REEL/FRAME:022230/0991

Effective date: 20090128

Owner name: FUJITSU MEDIA DEVICES LIMITED, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MORIYA, AKIRA;KAWACHI, OSAMU;REEL/FRAME:022230/0991

Effective date: 20090128

AS Assignment

Owner name: TAIYO YUDEN MOBILE TECHNOLOGY CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FUJITSU MEDIA DEVICES LIMITED;REEL/FRAME:025095/0167

Effective date: 20100331

AS Assignment

Owner name: TAIYO YUDEN CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TAIYO YUDEN MOBILE TECHNOLOGY CO., LTD.;REEL/FRAME:025095/0893

Effective date: 20100331

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
LAPS Lapse for failure to pay maintenance fees

Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.)

FP Lapsed due to failure to pay maintenance fee

Effective date: 20150913

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362